The present invention relates an idling control system for an internal combustion engine of a type having two spark plugs by each cylinder.
In order to improve ignition performance and combustion speed of an internal combustion engine, various control systems have been proposed. Japanese Patent Provisional Publication No. 5-141336 discloses an engine control system for an internal combustion engine provided with two plugs for each cylinder. This conventional engine control system is arranged to select one of a one plug ignition mode and a two plug ignition mode according to the engine operating condition in order to improve a stability of engine combustion.